#include<stdio.h>
#include<unistd.h>
#include<signal.h>
#include<stdint.h>

volatile uint64_t num=1;

void sigcb(int no){
    num=0;
    printf("num:%ld\n",num);
}
int main(){
    signal(SIGINT,sigcb);
    while(num){
        num++;
    }
    printf("while over!\n");
    return 0;
}
